深亚微米飞行高度测量技术研究

介绍了国内外深亚微米飞行高度测量技术,重点研究了干涉测量法、全内反射法、电学测量法的工作原理,分析了各种测量技术的特点,指出了深亚微米飞行高度测量技术亟待解决的关键性问题.     

跨境数据流动监管立足国际,看国内解法

随着全球数字经济的快速发展,数据流动变得更加频繁,跨境数据流动监管议题也引起了全球层面的讨论.跨境数据流动监管最早出现在各国的个人数据保护立法中,旨在对个人数据从本国向境外的转移进行监管.     

基于安全认证的实验室管理系统的设计和实现

传统的实验室管理完全采用手工的方法,人工输入信息,一切均由管理人员手工完成,存在数据量大、准确性得不到保障、不利于快速查询信息等问题,严重增加管理人员的工作量,实验室利用率较低。以开放式、交互式、共享式为原则,建设一个信息安全可靠的实验室管理系统,可以很大程度的提高实验室的效率,提高管理水平。     

海外瞭望

业界公司近期业绩报告摘选 花臣公司 花臣公司本财年第二季度销售收入达到2.181亿美元,同比增长了29%,增长幅度最大的是食用香精业务。食用香精业务的销售收入目前已占到花臣总销售额的71.5%（而2000年时这一数字仅为33%）。分部门来看,第二季度高档原料的营收增长了13%,达到4 260万美元,食用香精营收增长25%,达到1.251亿美元。     

Study of the key factors affecting the triple grid lifetime of the LIPS-300 ion thruster

In order to ascertain the key factors affecting the lifetime of the triple grids in the LIPS-300 ion thruster,the thermal deformation,upstream ion density and component lifetime of the grids are simulated with finite element analysis,fluid simulation and charged-particle tracing simulation methods on the basis of a 1500 h short lifetime test.The key factor affecting the lifetime of the triple grids in the LIPS-300 ion thruster is obtained and analyzed through the test results.The results show that ion sputtering erosion of the grids in 5 kW operation mode is greater than in the case of 3 kW.In 5 kW mode,the decelerator grid shows the most serious corrosion,the accelerator grid shows moderate corrosion,and the screen grid shows the least amount of corrosion.With the serious corrosion of the grids in 5 kW operation mode,the intercept current of the acceleration and deceleration grids increases substantially.Meanwhile,the cold gap between the accelerator grid and the screen grid decreases from 1 mm to 0.7 mm,while the cold gap between the accelerator grid and the decelerator grid increases from 1 mm to 1.25 mm after 1500 h of thruster operation.At equilibrium temperature with 5 k W power,the finite element method(FEM)simulation results show that the hot gap between the screen grid and the accelerator grid reduces to 0.2 mm.Accordingly,the hot gap between the accelerator grid and the decelerator grid increases to 1.5 mm.According to the fluid method,the plasma density simulated in most regions of the discharge chamber is 1?×?10~(18)-8?×?10~(18)m~(-3).The upstream plasma density of the screen grid is in the range 6?×?10~(17)-6?×?10~(18)m~(-3)and displays a parabolic characteristic.The charged particle tracing simulation method results show that the ion beam current without the thermal deformation of triple grids has optimal perveance status.The ion sputtering rates of the accelerator grid hole and the decelerator hole are 5.5?×?10~(-14)kg s~(-1)and 4.28?×?10~(-14)kg s~(-1),respectively,while after the thermal deformation of the triple grids,the ion beam current has over-perveance status.The ion sputtering rates of the accelerator grid hole and the decelerator hole are 1.41?×?10~(-13)kg s~(-1)and 4.1?×?10~(-13)kg s~(-1),respectively.The anode current is a key factor for the triple grid lifetime in situations where the structural strength of the grids does not change with temperature variation.The average sputtering rates of the accelerator grid and the decelerator grid,which were measured during the 1500 h lifetime test in5 k W operating conditions,are 2.2?×?10~(-13)kg s~(-1)and 7.3?×?10~(-13)kg s~(-1),respectively.These results are in accordance with the simulation,and the error comes mainly from the calculation distribution of the upstream plasma density of the grids.     

新时期面向品质提升的城市设计工作思路探讨——以沈阳金廊核心段城市设计为例

沈阳金廊在快速发展十年之后,迎来了对规划建设总结和提升的阶段,本文在分析其建设现状基础上,结合新时期中央城市工作会议精神,从追求品质增长、发挥公共价值、增强设计指导性三方面开展本轮城市设计工作,包括继续按照最初谋划的金廊整体功能结构和空间结构进行严格控制,着重对公共领域的品质进行提升,并打造未出让地块为示范项目树立标杆,最终落实成管控文件。     

FANUC RAM轴在数控伺服冲床上的应用

在FANUC Oi PD数控系统的基础上,把RAM轴功能应用在数控伺服冲床上,通过模拟伺服适配器控制第三方驱动器和电机,选择M信号来指定冲压轴所处的动作模式,控制冲头上下移动的形式、速度,降低冲压噪声,提高效率。     

数控转塔冲床送料加速度的智能调节技术探讨

随着智能制造时代的到来,客户对数控转塔冲床的效率要求越来越高,而提高送料的加速度和最大速度是最好的方式。一般常见冲床的加速度均为固定不变的,导致机床在运行过程中无法完全发挥其应有的特性。本文通过循序渐进的方式对加速度的智能调节技术进行了分析研究。     

船舶机舱通风与结构对其火灾特性的影响

提出多层几何结构,运用过滤平衡方程组及Sma-gorinsky模型描述了多层几何结构、无通风管路多层几何结构及单层几何结构的船舶机舱火灾场,计算分析通风和结构等对火灾过程的影响。认为多层几何结构中气流在子区域内产生较强的涡旋,在中间区域呈上升趋势,其平台诱发顶棚射流;贫氧区与富氧区分界明显,子区域中氧气浓度自上而下降低。无通风管路多层几何结构中心区域气流呈下降趋势,在较小的空间尺度内,氧气含量梯度较小,上甲板高净热通量区域偏大。单层几何结构中气流呈上升趋势,净热通量最高值达20kW/m2,且火焰传播速度受气流分布影响较大。